1. Field of Endeavor
The present invention relates generally to the separation and/or purification of fluids under the influence of an electric field, and specifically, to the separation of charged particles from other fluid constituents according to their mobility within the electric field.
2. State of Technology
Traditionally charged particles have been separated by size or charge using the method of electrophoresis, where an electric field is applied to a sample inserted into agarose gel situated in between two metal electrodes. Once placed under the electric field, the charged particles migrate through the pores of the gel. The end result is bands of particles sorted by their size, with the longer particles traveling less distance through the agarose pores compared to the shorter particles. Analysis of the bands is difficult since the sample is set in the agarose gel, making extraction difficult. In addition, using this technique frequently requires the analyte be heavily pre-processed.
Electrophoresis has also been performed using a capillary tube where when an electric field is applied to the tube, the constituents of the sample migrate at different speeds depending on their electrophoretic mobility in the solution. The result is that over the distance of the tube, the sample concentrates in a particular location based on its electrophoretic mobility relative the other fluid constituents in the tube. When the concentrated sample exits the tube it must be captured. Once captured, the isolated analyte can be further analyzed. One of the problems associated with capillary electrophoresis is that the volume of sample is constrained to about 100 nL, Another problem is that capillary electrophoresis is also labor intensive since capturing the sample from the capillary tube requires attention at the exact moment the concentrated plug of sample exits the capillary.